THE FIRST ANNUAL MISSISSIPPI COLONIAL WATERBIRD COUNT

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1 .~~---~~----_._ Vol. 25(1), July 1995 THE FIRST ANNUAL MISSISSIPPI COLONIAL WATERBIRD COUNT Allan J. Mueller U.S. Fish and Wildlife Service 2524 South Frontage Road, Suite B Vicksburg, MS Knowledge ofwildlife munbers and population trends is essential for sound management. The abundance of game animals is monitored through hunter check stations, Mourning Dove (Zenaida macroura) coo COlillts, American Woodcock (Scolopax minor) display censuses, midwinter waterfowl counts, and other techniques. We count nongame land birds and other birds using breeding bird surveys, breeding bird censuses, Christmas bird counts, spring migration counts, midwinter eagle counts, hawk watches, MAPS stations, standardized point counts as established through the Partners in Flight program, and general bird watching. The International Shorebird Survey counts shorebirds at concentration points and several states have annual or sporadic censuses ofcolonial nesting waterbirds. Mississippi has at least minimal monitoring for each ofthese bird groups except the colonial waterbirds. Although some colonial waterbird population data exist for Mississippi (Jackson and Jackson 1985, Jackson et al. 1979, Keller et al. 1984, and Portnoy 1977) there is no systematic, statewide data base. In 1994 the U.S. Fish and Wildlife Service and the Mississippi Museum ofnatural Science coordinated the first Mississippi Colonial Waterbird Count (MCWC). The ultimate objectives of the MCWC are to determine (l) the locations ofwaterbird colonies in Mississippi, (2) the species composition of each colony, and (3) the number ofnesting pairs of each species each year. In this report I provide some ofthis information as a summary ofthe first year efforts ofthe MCWC.

2 THE MISSISSIPPI KITE 9 METHODS The MCWC is a cooperative program that relies on a statewide cadre of volunteers to do most of the counting. Standard data sheets were distributed to cooperators and a fixed count period, 1-19 June, was established, although counts made during any part ofthe breeding season were accepted. The U.S. Fish and Wildlife Service counted colonies from a fixed-wing airplane on two days in the Delta counties and Claiborne County. The National Park Service conducted a one-day aerial count on the coast. The U. S. Army Corps of Engineers, Memphis District, traveled the entire Mississippi portion of the Mississippi River by boat to count Least Tern (Sterna antillarum) colonies. In some cases the number ofnests were counted, but this usually was not possible. Most counts were based on estimates ofthe number ofnests or the number of adults present, using the assumption that one adult was attending each nest at any given time. Generally aerial counts are not as accurate as counts made from the grolmd, The count period was selected to measure colony size during the peak nesting ofas many species as possible, however, early nesting species, such as the Great Blue Heron (Ardea herodias), were likely past their peak. VOLUNTEER PARTICIPATION Twenty-three people participated in data collection. Most are dedicated amateurs interested in the welfare of colonial waterbirds. The few professional biologists who participated did so as an extra duty that, with one exception, was not part oftheir normal responsibilities. In this first year ofthe MCWC, participants had to find the colonies as well as census them. Colony location will continue to be an important task for future counts. Observers were lacking for large areas ofthe state.

3 10 Vol. 25(1), July 1995 WATERBIRD POPULATIONS Sixty colonies were located and 18,954 breeding pairs of 12 species were reported (Table 1). Specific localities and data/observer are on file at the Mississippi Museum ofnatural Science and with the Vicksburg Office ofthe U.S. Fish and Wildlife Service. Cattle Egrets (Bulb ulcus ibis) were the most abundant species and Least Terns occurred in the most colonies (Tables 2 and 3). Nesting Tricolored Herons (Egretta tricolor) were found only in the Fitler Colony in Issaquena County. The Fitler Colony also had the only recorded nesting White Ibis (Eudocimus albus) and Black-crowned Night-Herons (Nycticorax nycticorax). Yellow-crowned Night-Herons (Nyctanassa violacea) were found nesting only at the Mule Jail Colony in Hinds COlliIty. Black Skinlmers (Rynchops niger) nested only at two coastal colonies, Long Beach Colony in Harrison County and Horn Island Pass Colony in Jackson County. Least Terns nested only on the coast and on the Mississippi River. The interior population nested at 34 locations (an estimated 1,070 pairs) on the Mississippi River, 17 colonies in Mississippi waters, 15 in Arkansas, and two in Louisiana adjacent to Mississippi. The Pearl River Refuge Colony in Madison COWlty was the largest colony in the state, with 5,826 breeding pairs offour species, including 5,240 Cattle Egret pairs. In the Delta, Fitler was the largest and most diverse colony with seven species and 1,637 breeding pairs. The Gulfport East Colony (Harrison County) was the largest coastal county, with 900 pairs of Least Terns and pairs ofblack Skimmers. No colonies were found in Hancock County, which conforms with the findings of previous coastal surveys (Jackson and Jackson 1985, Jackson et a , Keller et a , Portnoy 1977). In this first year ofthe MCWC, many colonies (but an unknown number) were missed. COllilting effort was highest in the Delta counties and on the coast, but even in these areas coverage was not complete. Only the coast has any historical data to use for trend analysis and those are incomplete. From Least Tern nesting on the coast averaged approximately 4,300 pairs (Jackson and Jackson 1985), but la. Jackson, l Dubuisson, and G. Hopkins reported only 2,076 pairs in 1994 (Table 2). No other tern species were fowld nestingon the coast in From 1976 to 1979, nesting by other tern species was irregular (Jackson et a ). The 73 pairs of Black

4 THE MISSISSIPPI KITE 11 Skimmers are also within the historical range ofvariation in nesting activities in coastal Mississippi. In future years we hope to enlarge the cadre of volunteers, achieve more complete coverage of the state, and improve the quality/uniformity of estimates. Table 1. County/Regional Swnmary for the 1994 Mississippi Colonial Waterbird Count. Number of Number of Number of Colonies Species Pairs Statewide ,954 Delta counties ,278 (including MS. River in MS) Mississippi River (in AR or LA)a Coastal counties ,157 Adams Co Calhoun Co Claiborne Co Hinds Co Jefferson Co Madison Co ,826 a Least Tem colonies on the Mississippi River adjacent to Mississippi, but in Arkansas or Louisiana.

5 12 Vol. 25(1), July 1995 Table 2. Species Summary for the 1994 Mississippi Colonial Waterbird Count. SPECIES NUMBER NUMBER LARGEST OF OF COLONY PAIRS COLONIES STATEWIDE Anhinga (Anhinga anhinga) Great Blue Heron Great Egret 1, (Casmerodius a/bus) Snowy Egret (Egretta thu/a) Little Blue Heron 2, ,000 (Egretta caeru/ea) Tricolored Heron Cattle Egret 10, ,240 Black-crowned Night-Heron Yellow-crowned Night-Heron White Ibis Least Tern 2, Least Tern a Black Skimmer a Colonies on the Mississippi River adjacent to Mississippi, but in Arkansas or Louisiana.

6 THE MISSISSIPPI KITE 13 Table 3. Species Summary for Various Regions of Mississippi for the 1994 Mississippi Colonial Waterbird Count. SPECIES NUMBER NUMBER LARGEST OF PAIRS OF COLONY COLONIES DELTA COUNTIES Anhinga Great Blue Heron Great Egret 1, Snowy Egret Little Blue Heron 11, ,000 Tricolored Heron Cattle Egret 4, ,750 Black-crowned Night-Heron White Ibis Least Tern Least Tern a COASTAL COUNTIES Great Blue Heron Least Tern 2, Black Skimmer ADAMS COUNTY Great Egret Least Tern

7 14 Vol. 25(1), July 1995 Table 3. Continued. ISpecies Number of Number of Largest Pairs Colonies Colony CALHOUN COUNTY Anhinga Great Blue Heron ~==sn==o=wy==e==gr==e=t ===C=L=A=I=B=;Ir=~=E=5~=O=UN=;=1 =T=Y=l==;===50=~ HINDS COUNTY Great Blue Heron Yellow-crowned Night-Heron Least Tern JEFFERSON COUNTY I 40 I 1 I 40 MADISON COUNTY Anhinga Snowy Egret Little Blue Heron Cattle Egret 5, ,240 a Colonies on the Mississippi River adjacent to Mississippi, but in Arkansas or Louisiana.

8 THE MISSISSIPPI KITE 15 ACKNOWLEDGMENTS Participants in the 1994 MCWC were Robert W. Alexander, Ben Blackwell, Nick Blanton, Rick M. Cummins, Maurice V. Duvic, Janet T. Dubuisson, Buddy Ethridge, James P. Hooper, Gary W. Hopkins, Jerome A. Jackson, Bette J.S. Jackson, 1. Calvin Lunceford, Gene C. Knight, Shannon V. Knight, Larry E. Marcy, Keith M. McCartney, Harold A. Morrow, Allan J. Mueller, Charles Reitan, John P. Rumancik, Mary P. Stevens, Carrie A. Straight, and Jeff Terry. Mark Woodrey reviewed this paper and assisted in coordination ofthe counts. LITERATURE CITED Jackson, J.A., and BJ.S. Jackson Status, dispersion, and population changes ofthe Least Tern in coastal Mississippi. Colonial Waterbirds 8: Jackson, J.A., BJ. Schardien, and CD. Cooley Dispersion, phenology, and population sizes of nesting colonial seabirds on the Mississippi Gulf Coast. Proc Conf. Colonial Waterbird Group 3: Keller, C.E., J.A. Spendelow, and R.D. Greer Atlas of wading bird and seabird nesting colonies in coastal Louisiana, Mississippi, and Alabama: U.S. Fish and Wildlife Service, FWS/OBS-84/ pp. Portnoy, J. W Nesting colonies of seabirds and wading birds coastal Louisiana, Mississippi, and Alabama. U.S. Fish and Wildlife Service, FWS/OBS-77/ pp.